Apparently it's really important, but everyone seems to have a different opinion on where you should sit.

More details on "where/how you bet/play in relation to where the button is" please

So... in a big table, ATo is a good -- but not excellent -- hand that sits right on the "playability" line. You should only play it if you know there's a good reason to -- which may be provided to you, if you're on the button.

The reason you should fold ATo if you're UTG is because someone will probably raise and put you in the unfavorable situation.

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Think of it this way.

If you are under the gun at a 9-person table then you are competing against all 9 of those players -- if you have A-10o then you'd have to hope that all 9 of those players don't have a better hand in order for you to have the best hand.

On the other hand, if everyone has folded to you on the button then you are only competing against 2 players (the small blind and the big blind) so if you have A-10o then it's much more likely that neither of them has a better hand.

So when you are about to act before the flop ask yourself "How many players am I competing against?" If the answer is very few then you are more likely to win the hand than if you are still competing against a lot of players.

Position is also very important after the flop although strategies vary. Most people agree that acting last in a hand (after the flop) -- i.e. on the button or as close to the button as possible -- is a huge advantage.

Let's say you have QJ and you are on the button (and for some reason haven't already folded) with 4 others in the hand. Let's say the flop is Q83 with no two cards of the same suit and let's say that everyone checks to you. This likely means that no-one has a Q (because they probably would have bet if they had a Q since they would want to knock out anyone with an A or K) so you likely have the best hand -- this is very valuable (though not certain) information and you can act based upon this information. Even if you don't have a Q you can bet 2/3 of the pot size to pretend that you have a Q and maybe the others will fold since they might believe you. The information is not always correct but most people believe it is a huge advantage to act last after the flop.

Take it the other way around and let's say you have that hand and that flop but have to act first. You have almost no idea what anyone else has (because they haven't acted yet after the flop) and so you are at a disadvantage.

These examples are all simplistic and not fully representative of real play but hopefully they show that position is very important hold-'em poker.

basically
blinds and UTG are bad positions because they are early positions - first to act.
And because you are the first to act, your action gives away information that the person with late positions (like those in the dealer's position) who act after you can use and exploit.
the main reason late position is good is that you can bluff more effectively. If everyone else checks to you and there is no one acting after you, most of the time nobody has crap. so use that position to bluff away those pots.

Lots of good advice here... Thanks.

So... I'm assuming it's better to sit on the left of someone who bets a lot. And to the right of someone who checks/calls a lot...

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